1. Field of the Invention
The present invention relates to an application apparatus for mounting, to a photomask, a pellicle assembly including a pellicle film and a support frame, and to a pressure body for pressurizing the photomask and the pellicle assembly in the application apparatus.
2. Description of Related Art
Conventionally, a pellicle mounting apparatus for mounting a pellicle assembly to a photomask has been known. An example of such a pellicle mounting apparatus is described in Patent document 1.
FIG. 13 is a perspective view illustrating a photomask 70 and a pellicle assembly 80. The photomask 70 is an original plate for forming, using optical transfer, an inner circuit of an electronic component such as a semiconductor device or flat-panel display. One of surfaces of the photomask 70 is a chromium surface (pattern surface) 71, and at the chromium surface 71, there is formed an exposure pattern region 71a in which a circuit pattern is defined. The other surface of the photomask 70 is generally called a glass surface 72.
The pellicle assembly 80 means a pellicle film provided with a frame, and includes a pellicle film 81 and a pellicle frame 82. The pellicle film 81 is placed onto a lower surface of the pellicle frame 82. The pellicle assembly 80 is used in order to fix the pellicle film 81 to the photomask 70. The pellicle assembly 80 fixed to the photomask 70 protects the chromium surface 71 from dust.
The pellicle mounting apparatus sandwiches the photomask 70 and the pellicle assembly 80, and presses them to each other. In this case, the pellicle frame 82 is provided, at its upper surface, with an adhesive layer 90. Therefore, the photomask 70 and the pellicle assembly 80 are pressurized, thereby mounting the pellicle assembly 80 to the photomask 70.
Currently, the dominating photomask for semiconductor is formed into a square whose sides are each 152 mm (6 inch) long, and whose thickness is about 6.3 mm. This photomask is generally called a “6-inch mask” or “6025” photomask. In the case of the 6-inch photomask, a pellicle assembly is mounted to a chromium surface so that a pellicle film covers an exposure pattern region of the chromium surface.
Depending on a semiconductor fabrication process, another photomask for semiconductor may also be used. This photomask for semiconductor is formed into a square whose sides are each 126.6 mm (5 inch) long, and whose thickness is about 2.3 mm. In the case of the 5-inch photomask, a pellicle assembly may be mounted to a chromium surface, or a pellicle assembly may be mounted to both of a chromium surface and a glass surface.
In a pellicle mounting apparatus, the positions of a photomask when a pellicle assembly is mounted to the photomask generally include the following two positions. In a first position, the photomask is held horizontally, and a chromium surface is facing downward. In a second position, the photomask is held perpendicularly, and the chromium surface is facing horizontally. Naturally, the position of the pellicle assembly to be mounted to the photomask is also set to correspond to the position of the photomask.
FIG. 14 is a front view illustrating principal parts of a conventional pellicle mounting apparatus 1. The pellicle mounting apparatus 1 is a horizontal type. In the pellicle mounting apparatus 1, a photomask 70 is held horizontally. The pellicle mounting apparatus 1 includes, from the bottom to the top, a lower air cylinder 2, a lower base member 3, a pellicle pressure body 4, a mask pressure body 5, and an upper base member 6. Between the pellicle pressure body 4 and the mask pressure body 5, a pellicle assembly 80 and the photomask 70 are located at lower and upper positions, respectively. In this case, the pellicle assembly 80 is placed on the pellicle pressure body 4, and the photomask 70 is placed on a frame-like stage (not illustrated) for supporting the photomask 70.
In the pellicle mounting apparatus 1, the pellicle pressure body 4 is moved upward by driving of the lower air cylinder 2. The pellicle pressure body 4 rises while pushing up the photomask 70 via the pellicle assembly 80. The pellicle pressure body 4 and the mask pressure body 5 constitute a pair of indenters, and the photomask 70 and pellicle assembly 80 located therebetween are pressurized. As a result, the pellicle assembly 80 is mounted to the photomask 70 via the adhesive layer 90.
The pellicle mounting apparatus 1 is formed so as to be capable of coping with changes in sizes of the pellicle assembly 80 and photomask 70. Specifically, in accordance with different sizes of the pellicle assembly 80 and photomask 70, the pellicle pressure bodies 4 and mask pressure bodies 5 of different sizes are prepared. Further, so as to be able to replace the pellicle pressure body 4 in accordance with the pellicle assembly 80, the pellicle pressure body 4 is attachable and detachable to and from the lower base member 3. So as to be able to replace the mask pressure body 5 in accordance with the photomask 70, the mask pressure body 5 is attachable and detachable to and from the upper base member 6.
The pellicle pressure body 4 and the mask pressure body 5 are molded products produced by performing machining on metal (hard aluminum) or engineering plastic. The pellicle pressure body 4 has a projected portion 4a that is brought into contact with only a pellicle frame 82 of the pellicle assembly 80, thus pressurizing only the pellicle frame 82. The mask pressure body 5 has a projected portion 5a that is brought into contact with only an outer peripheral portion of the photomask 70, thus pressurizing only the outer peripheral portion of the photomask 70. In this case, the outer peripheral portion refers to a region of a glass surface 72, which is located outwardly of a patter region 71a on a chromium surface 71. It should be noted that pressurization of the photomask 70 includes not only a case in which the outer peripheral portion of the glass surface 72 is pressurized, but also a case in which an inner region of the glass surface 72 (i.e., a region of the glass surface 72, corresponding to the pellicle frame 82) is pressurized.
Patent document 1: Japanese Laid-Open Patent Publication No. 9-146261